Gear train arrangements

ABSTRACT

Gear train arrangements for transmitting a power from a driving source to a driven member at more than three speeds in one direction and another speed in the opposite direction, the gear train arrangements using basically three planetary gear sets and at least five friction elements such as clutches and brakes which are selectively actuated to selectively engage the rotary members of the three planetary gear sets to deliver an output power at the above said speeds. The gear train arrangements are specifically adapted for use in an automatic transmission system of a motor vehicle using a torque converter or fluid coupling.

Hittite States Patnt [191 1111 3,863,524 Mori et al. Feb. 4, 1975 GEAR TRAIN ARRANGEMENTS 3,264,902 8/1966 Breting et al.; 74/764 [751 Yoichi Mort, Yokohama; Nobuo iiSJS $3323 31123111?" 33:31:..7391335 0kaZaki, C hlgaSflk1;K"ni Ohisuka; 3,410,157 ll/l968 Livezey 1. 74/764 x Tets ya u both of yo all of 3 446,092 3/1969 Moan 74/764 x Japan [73] Assignee: Nissan Motor Company, Limited, Primary ExaminerSamuel Scott Yokohama, Japan Assistant Examiner-P. S. Lall [22] Filed, Sept 13 1972 Attorney, Agent, or Firm-Depaoli & OBrien [21] Appl. No.: 288,553 57 ABSTRACT Related [1.8. Application Data 1 [62] Division of 5 30 496 April 21 1970 No Gear train arrangements for transmitting a power from 3,701,293. 7 a a driving source to a driven member at more than three speeds in one direction and another speed in the [30 Foreign Appncation p i Data gpposiltle dLrfiCfiOIit, the gear train arrandgemelnts usfing asica y t ree panetary gear sets an at east 1ve July 1969 Japan 44 55068 friction elements such as clutches and brakes which [52] U S Cl 74/765 74/759 are selectively actuated to selectively engage the ro- [511 57/10 tary members of the three planetary gear sets to de- [58] Field 765 759 liver an output power at the above said speeds. The gear train arrangements are specifically adapted for [56] References Cited use in an automatic transmission system of a motor ve- UNITED STATES PATENTS hicle using a torque converter or fluid coupling.

3,234,820 2/1966 Tuck et al 74/765 X 2 Claims, 37 Drawing Figures lOb lOo PATENTEDFEB 4W5 3.863.524

SHEET OQUF 15 INPUT OUTPUT PATENTEB EB 19 SHEET 06 0F '15 Fig. 60

OUTPUT INPUT PiTENTED 41% 3,863,524 saw 080; 15

INPUTKF) OUTPUT INPUTHR) PATENTEDFEB 3.863.524 SHEET USUF 15 INPUT( F) OUTPUT IN R) PATENTED 3.863.524 sum mar 15.

INPUT OUTPUT PATENTED 4W5 3,863,524

SHEET 1m 15 Fig. /4

PATENTED M975 3, 863,524

GEAR TRAIN ARRANGEMENTS This is a division, of application Ser. No. 30.496, filed Apr. 21, 1970 now Pat. No. 3,701,293.

It relates to gear train arrangements for a transmission system of a motor vehicle and, more particularly, to gear train arrangements of planetary gear type adapted to provide basically four forward and one reverse vehicle speeds.

A usual gear train arrangement using a planetary gear system is made up of a combination of one or more, similar or different, planetary gear sets each having one or more planet pinions and is operated through actuation of friction elements such as clutches and brakes which are arranged to attain a desired combination of gear ratios. Typical of such gear train arrangement is the one that uses three simple planetary gear sets which are combined together to provide three forward and one reverse vehicle speeds. (It may be noted that the term simple planetary gear set as herein used is intended to refer to a planetary gear set having a single planet pinion.)

Foremost of the practical requirements of a gear train arrangement to attain an increased number of vehicle speeds is a wide selection of the combinations of gear ratios, which requirement, however, is reflected by an increased number of component parts of the gear train arrangement and complicated gear shifting operations.

In order that the gear train be snugly accommodated within a limited space in the transmission system, every component of the planetary gear system should be as small in dimensions as possible. From the view point of production economy, moreover, it is desired that the number of the component parts of the gear train be reduced to a minimum and that the parts corresponding 'in function be fabricated to be common in geometry to.

one another so as to permit ofquantity production. Another important requirement of the gear train of a transmission system is the ease of gear shifting operations.

It is, therefore, an object of the invention to provide gear train arrangements adapted to provide basically four forward and one reverse vehicle speeds.

Another object is to provide gear train arrangements providing essentially four forward and one reverse vehicle speeds with wide selection ofthe combinations of gear ratios.

Still another object is to provide gear train arrangements providing four, or even more, forward and one reverse vehicle speeds, which arrangements are constructed with a practically minimum number of component parts and nevertheless can provide practically any desired combination of gear ratios.

Still another object is to provide gear train arrangements that are suited for quantity production.

Still another object is to provide gear train arrangements providing four, or even more, forward and one reverse vehicle speeds with utmost ease of gear shifting operations.

In order to achieve these and other objects, the invention proposes to use various combinations of basically three substantially identically sized planetary gear sets which are operated by means of two or three clutches and two or three brakes. The gear train arrangements using such combinations can be readily modified with incorporation of additional minor arrangements into those providing five or six forward'and one reverse vehicle speeds.

In the drawings:

FIGS. 1 to 8 are sectional views schematically showing various preferred embodiments of the invention. each of which embodiments uses three planetary gear sets with two clutches and three brakes to provide four forward and one reverse vehicle speeds;

FIG. 9 is similar to FIGS. l to 8 but shows other em bodiment using three planetary gear sets with three clutches and two brakes to provide four forward and one reverse vehicle speeds;

FIGS. 10, II, and I2 are views illustrating still other embodiments using three planetary gear sets with three clutches and three brakes to provide four forward and one reverse vehicle speeds;

FIG. I3 is a view illustrating still another embodiment using three planetary gear sets with three clutches and three brakes to provide five forward and one reverse vehicle speeds;

FIG. 14 is a view illustrating still another embodiment using four (including one auxiliary) planetary gear sets with three clutches and four brakes to provide four forward and one reverse vehicle speeds;

FIG. 15 is a view illustrating still another embodiment using four (including one auxiliary) planetary gear sets with two clutches and three brakes to provide five forward and one reverse vehicle speeds;

FIG. 16 is a view illustrating still another embodiment using four (including one auxiliary) planetary gear sets with three clutches and four brakes to provide six forward and one reverse vehicle speeds;

FIG. 17 is a view illustrating still another embodiment using four planetary gear sets with three clutches and five brakes to provide an overdrive from the fourth speed;

FIGS. 1a to 16a are diagrams each showing the different revolution speeds of the individual rotary members of the planetary gear sets used in the embodiment illustrated in the corresponding figure out of FIGS. 1 to 16; and

FIGS. lb, 4b, 6b, 7b, 8b, 9b and 10b are views each showing a modification of the embodiment illustrated in the corresponding figure without the subscript.

Corresponding reference numerals and characters represent like members in all the figures.

It may be noted in regard to the drawings that only the upper half of each gear train arrangement is herein shown for simplicity of illustration because the gear train arrangement is generally symmetrical with respect to the input and output shafts.

First referring to FIG. 1, the gear train according to one embodiment of the invention is, as customary, connected at one end with an engine through an input shaft 10 and a torque converter or fluid coupling (not shown) and at the other end with a differential (not shown) through an output shaft 11 of the transmission system.

The gear train as shown includes a first, second and third planetary gear sets l2, l3 and! 14, all of which are constructed as simple planetary gear sets which are fabricated to be substantially identical in geometry with each other.

The first planetary gear set 12 comprises an outer ring gear R a planet pinion P meshing with the outer ring gear, and a sun gear S, meshing with the planet pinion. The second planetary gear set 13 similarly comprises an outer ring gear R a planet pinion P meshing with the ring gear, and a sun gear S meshing with the planet pinion. The third planetary gear set 14 also similarly comprises an outer ring gear R;,, a planet pinion P, meshing with the ring gear, and a sun gear 5 meshing with the planet pinion. The planet pinions P,, P, and P are carried on and revolved by pinion carriers l5, l6 and 17, respectively, The ring gears, pinion carriers and sun gears are all rotatable about a common axis which is in line with the axes of the pinion carriers. More detailed discussion on the constructions and motions of the planetary gear set per se is herein omitted because they are well known in the art.

The ring gear R, of the first planetary gear set 12 is constantly connected to and rotatable with the planet pinion P of the second planetary gear set 13 through the pinion carrier which forms part of a drum 18. The sun gears S, and S of the first and second planetary gear sets 12 and 13, respectively, are constantly connected to and rotatable with the input shaft of the transmission through mechanical linkages 19 and 20, respectively. The ring gear R is constantly connected to and rotatable with the sun gear 5, of the third planetary gear set 14 through a drum 21. The pinion carrier 17 is constantly connected to and rotatable with the output shaft 11 of the transmission to carry an output power to the differential (not shown).

The pinion carrier of the planet pinion P, is connected to a first band brake B, which, when applied, holds the pinion carrier 15 stationary. The drum 18 interconnecting the ring gear R, and pinion carrier 16 co acts with a second band brake B, which, when applied, holds both the ring gear R, and pinion carrier 16 stationary. The drum 2linterconnecting the ring gear R and sun gear S coacts with a third band brake B, which, when applied, holds both the ring gear R and sun gear S, stationary.

Two clutches C, and C are provided to selectively connect the ring gear R, to the drum 21 and the input shaft 10, respectively.

Now, it is well known in the art that, assuming the revolution speeds of a ring gear, sun gear and pinion carrier of a given planetary gear set are Nr, Ns and Np, respectively, and the ratio ofthe number of teeth of the sun gear to the number of teeth of the ring gear is a, then the following equation holds:

(a +1)*Np Nr a'Ns.

Thus, for the planetary gear sets l2, l3 and 14, the following equations can be derived:

( 1' P1 Nr1 OWNS (04 'l' Nrg az'Nsz, and

( s )'Np Nr, a -Ns where the subscripts l, 2 and 3 represent the first, second and third planetary gear sets 12, 13 and 14, respectively.

In consideration of the constant connections between some of the rotary members of the planetary gear sets, the following equations hold:

N5, N5 Nr, N1 2, and Nr, Ns,

The speeds Ns, and Np, are equal to the revolution speeds of the input and output shafts 10 and l 1, respectively.

These mathematical relations between the revolution speeds of the individual rotary members of the planetary gear sets can be graphically illustrated in FIG. la. wherein points L, M and N are given on a line 0-0 in such a manner that the following relations are maintained:

OL/LM 01,, ON/NO' a and O'L/LO 01,.

Thus, the points 0, L, M. N and 0' stand for the relations between those individual rotary members of the planetary gear sets which are respectively shown below these points. The speed vector of each rotary member of the planetary gear sets is indicated by a length from the respective point 0, L, M, N or O on a line extending therefrom.

When, in operation, the first speed is to be selected, the second clutch C is coupled and the first brake B, applied. The ring gear R of the third planetary gear set 14 now rotates with the input shaft 10 and the pinion carrier 15 is held stationary, so that the following equations hold:

Ns Nr,, and Np, 0.

In this condition, the sun gear S, is rotated directly by the input shaft 10 with the pinion carrier 15 held stationary so that the ring gear R, and the pinion carrier 16 of the planet pinion P rotate at a speed corresponding to a vector NN, in FIG. 1a. With the sun gear 8, rotating with the input shaft 10, the ring gear R and the sun gear 8,, rotate at a speed corresponding to a vector O'O,. The ring gear R rotating with the input shaft and the sun gear S rotating at a speed corresponding to O'O',, the pinion carrier 17 of the planet pinion P rotates at speed corresponding to LL, providing a gear ratio for the first forward vehicle speed.

The gear ratio establishing the first speed thus delivered from the output shaft 11 is thus expressed as:

When the vehicle speed is to be shifted from the first to the second speed, then the first brake B, is released and instead the second brake B is applied with the second clutch C kept coupled. Thus:

Nr Npg 0,

With the brake 3, applied, the pinion carrier 16 is held stationary and the sun gear S rotates with the input shaft 10 so that the ring gear R and the sun gear S, are rotated at a speed corresponding to a vector 0'0, in FIG. 1a. With the clutch C coupled, the ring gear 5, rotates with the input shaft 10 so that the pinion carrier 17 of the planet pinion P, rotates at a speed corresponding to a vector LL, providing a gear ratio for the second forward speed.

The gear ratio for the second vehicle speed is thus expressed as:

When the speed is to be shifted from the second to the third speed, the second brake B is released and instead the third brake 8;, applied with the second clutch C kept coupled. Thus:

Nrg N53 O and Nra N52.

With the brake 8,, applied and the clutch C coupled, the sun gear 8;, is held stationary and the ring gear R rotates with the input shaft 10 so that the pinion carrier 17 of the planet pinion P rotates at a speed corresponding to a vector LL which provides a gear ratio to establish the third forward speed.

The gear ratio for the third speed is thus expressed as:

brake is kept released. The gear ratios indicated in the parentheses are derived on the assumption that or, a a 0.45. (This will apply to all the tables which are hereinafter presented.)

Table l C, C2 B, B2 B1 Gear Ratios F lst 1 11 188) o l-a,a,,a,u;,( l+or- I w l+0r;, I 1.82) it 2nd l-a. a,, T a 3rd 1+0, t 1.45

h I l [.00]

Rev l (-2.22)

Ns,/Nc l a,,. In order to streamline the shifting between the first When the Speed is to be shifted from the third to the P Second Speeds h chhch 23 may be fourth speed, then the third brake B, is released and the on h planet l 15 of h planetary gear first clutch C, coupled with the second clutch C kept set as Illustrate! m If u led Thus, it WIll bC appreciated that the gear train shown in c0 p N N FIGS. 1 and lb are suited to provide ease of gear shift- T T 25 ing operations because the gear ratios can be changed With the brakes B,, B and B released and the merely by releasing only one of the clutches and brakes clutches C, and C coupled, all the planetary gear sets and actuating another one of them. rotate with the input shaft so that the revolution speed FIG, 2 illustrates another form of the gear train acof the pinion carrier 17 of the planet pinion P3 is equal cording to the invention. The gear train is constructed t0 the speed Of the input shaft, as indicated by a vector so as to provide four forward and one reverse speeds 4 in I l with use of three identical planetary gear sets l2, 13 The gear ratio for the fOUI'th speed attained In this and are perated two Clutches C and C2 manner is thus expressed s: and three band brakes B,, B and 8,.

N /N l The first clutch C, is linked on the one hand with the input shaft 10 of the transmission and on the other with When the ehicl t8 t be mo bflCkWZU'dl), the firs the ring gear R, of the first planetary gear set 12. The lu i is Coupled and the second brake 2 pp second clutch C,, which is also linked with the input Thus: shaft 10, is linked with both the sun gears S, and S of Nr Nr and Nr, Np 0. the first and second planetary gear sets 12 and 13, re- With the brake B2 applied and the sun gear 52 romp 40 spectively, through a drum 24 for the first band brake ing with the input shaft 10, the ring gear R and the sun 1 he Shh gears 51 and 52 are result cohstahhy gear 53 rotate at aspeed Corresponding to a vector connected together and rotatable with each other. The O'O Since, in this instance, the clutch C, is coupled, plhhet plh'oh P1 ofthe first plahetawgear the ring gear R8 also rotates at a speed equal to the stantly connected to and rotatable with the ring gear R speed of the ring gear R and sun gear 8,. B h h i Of the second planetarys gear set 13, sun gear 5, of the gear R2 and Sun gear 53 rotating at the Speed Corre third planetary gear set 14, and output shaft 11 of the sponding to OO the planetary gear s t 14 rotates in transmission through the pinion carrier 15 and an interits entirety at this speed. The output shaft 11 is thus romechate Shaft h plahet P'hmh P2 of the Second tated at a Speed corresponding to LLr in a direction planetary gear set 131s constantly connected to and roposite to the rotation of the input shaft tatable with the planet pinion P of the third planetary The gear ratio for the reverse speed thus established gear set 14 through the Pihioh Carriers 16 and 17 which is thus expressed form part of a drum 26 for the second band brake B The ring gear R of the third planetary gear set 14 is Nsl/Np-1 connected to a drum 27 for the third band brake B The conditions of the clutches and brakes for the dif- The conditions of the clutches and the brakes for the ferent vehicle speeds and the gear ratios attained under different vehicle speeds and the gear ratios attained in these conditions are tabulated in Table I, wherein the these conditions are tabulated in Table II; the gear rasign refers to that the related clutch or brake is actios are calculated in a manner similar to that discussed tuated and the sign refers to that the clutch or in connection with the gear train of FIG. 1.

Table ll C, C2 B, B.) 8,, Gear Ratios F lst l+d,+a,/u 2.45)

2nd l+rr,/ora,(a-,a;,)/a l+(r Hi2) W Li r 3rd l +0, L45) a 4th l t 1.00 Rev. l/a 2.22)

When the first forward speed is selected, the clutch C, is coupled and the brake B applied. In this instance, the operations of the individual rotary members will be easily understood if it is assumed that the output shaft 11 is first rotated to impart a rotational effort to the input shaft 10, conversely to the actual operation. Thus, if the output shaft 1] is rotated at a speed corresponding to a vector AA, in FIG. 2a, then the ring gear R and the pinion carrier 15 of the planet pinion P, will rotate at the same speed as the output shaft 11. With the brake B applied, the planet pinion P is held stationary so that the sun gears S and S, rotate at a speed corresponding to a vector OO,. Such rotation of the sun gear S, and the pinion carrier 15 (which revolves at a speed equal to the revolution speed of the output shaft 11) will dictate the speed at which the ring gear R, of the first planetary gear set 12 rotates as represented by a vector OO in FIG. 2a. The driving force is actually carried to the input shaft 10, not to the output shaft 11, so that the flow of rotation is exactly inverse from that discussed above. Thus, it is apparent that the first speed corresponds with the vector LL, in FIG. 2a.

When the speed is shifted from the first to the second speed, then the brake B is released and the brake B is applied with the clutch C, kept coupled. Here, it is also assumed that the driving force is initially transferred to the output shaft 11. lf the output shaft 11 is rotated at a speed corresponding to a vector LL, in FIG. 2a, the sun gear 5 rotates with the output shaft 11. The ring gear R being held stationary with the brake 3,, applied, the pinion carriers 17 and 16 rotate at a speed corresponding to a vector MM,. Since, in this instance, the ring gear R, rotates with the output shaft 11 at a speed corresponding to the vector LL the sun gears S and S, rotate at a speed corresponding to the vector 00,. The planet pinion P, is rotated with the pinion carrier rotating with the output shaft 11 so that the ring gear R, will rotate at a speed corresponding to the vector 00 in FIG. 2a. The actual operations of the planetary gear sets are exactly converse from those discussed above but, anyway, it is apparent that the second speed corresponds to the vector LL, in FIG. 2a.

When the speed is shifted from the second to the third speed, the brake B, in lieu ofthe brake 8,, is now applied with the clutch C, kept coupled, so that the sun gears S, and S are held stationary and the ring gear R, rotates with the input shaft 10. The pinion carrier 15 supporting the planet pinion P,. therefore, rotates at a speeds corresponding to a vector LL, providing a gear ratio for the third forward speed.

When the speed is further shifted up from the third to the fourth speeds, all the brakes are released and the clutches are coupled so that the first planetary gear set 12 rotates in its entirety at the same speed as the input shaft 10. The speed of the input shaft 10 is in this manner transferred to the output shaft 11 as it is.

For effecting the reverse movement of the vehicle, the clutch C is coupled and the brake 8: applied. The sun gear 5 now rotates with the input shaft 10 with the pinion carrier 15 held stationary so that the ring gear R rotates at a speed corresponding to a vector LL, which provides a gear ratio to establish the reverse speed.

lt will now be appreciated that the gear train of FIG. 2 is, similarly to that of FIG. 1, adapted to provide ease of gear shifting operations because the gear ratios can be changed merely by releasing only one of the clutches and brakes and actuating another one of them.

FIG. 3 illustrates still another form of the gear train according to the invention constructed to provide four forward and one reverse speeds. The gear train also has three identical planetary gear sets l2, l3 and 14 with two clutches C, and C and three brakes B,, B and 8,, as shown.

The first clutch C, is linked on one side with the input shaft 10 and on the other with the ring gear R, of the first planetary gear set 12 through a drum 28 of the first band brake B,. The second clutch C is linked on one side with the input shaft 10 and on the other with the sun gears 8,, S and S of the first, second and third planetary gear sets l2, l3 and 14, respectively, through an intermediate shaft 29. The sun gears 5,, S and S, are thus constantly connected to each other and rotatable with the input shaft 10 when the clutch C is coupled. The pinion carrier 15 of the planet pinion P, of the first planetary gear set 12 is constantly connected to and rotatable with the ring gear R of the second planetary gear set 13 through a drum 30 for the second band brake B The pinion carrier 16 of the planet pinion P of the second planetary gear set 13 is constantly connected to and rotatable with the ring gear R of the third planetary gear set 14 and is linked with the third brake B, through a drum 31. The pinion carrier 17 of the planet pinion P of the third planetary gear set 14 is connected to the output shaft 11. A one-way brake 32 is provided to prevent the pinion carrier 16 and ring gear R,, from rotating in a direction opposite to the rotation of the input shaft 10.

In consideration ofthe constant connections between some of the rotary members of the planetary gear sets in this embodiment, the following relations hold:

Np, Nr,,, Np, Nr, and Ns, Ns, N53.

The conditions ofthe clutches and brakes for the different vehicle speeds and the gear ratios attained in these conditions are tabulated in Table III. 

1. A gear train comprising: an input shaft (10); an output shaft (11); a first planetary gear set (12) having a ring gear (R1), a pinion carrier (15), a planet pinion (P1) meshing with the ring gear (R1) and rotatably journaled on the pinion carrier (15) and a sun gear (S1) meshing with the planet pinion (P1); a second planetary gear set (13) having a ring gear (R2) connected to the pinion carrier (15) of said first planetary gear set (12), a pinion carrier (16) a planet pinion (P2) meshing with the ring gear (R2) thereof and rotatably journaled on the pinion carrier (16) thereof and a sun gear (S2) meshing with the planet pinion (P2) thereof, the sun gear (S2) of said planetary gear set being connected to the sun gear (S1) of said first planetary gear set; a third planeary gear set (14) having a ring gear (R3) connected to the pinion carrier (16) of said second planetary gear set (13), a pinion carrier (17), a planet pinion (P3) meshing with the ring gear (R3) thereof and rotatably journaled on the pinion carrier (17) thereof and a sun gear (S3) meshing with the planet pinion (P3) thereof, the pinion carrier (17) of said third planetary gear set (14) being connected to said output shaft (11), the sun gear (S3) of said third planetary gear set being connected to the sun gear (S2) of said second planetary gear set; a first clutch means (C1) for engaging said input shaft (10) with the ring gear (R1) of said first planetary gear set (12) during operation of reverse speed and fourth forward speed; a second clutch means (C2) for engaging said input shaft (10) with the sun gears (S1, S2, S3) of said first, second and third planetary gear sets (12, 13, 14) during operation of first second, third and fourth forward speeds; a first brake means (B1) for anchoring the ring gear (R1) of said first planetary gear set (12) during operation of third forward speed; a second brake means (B2) for anchoring the pinion carrier (15) of said first planetary gear set (12) and the ring gear (R2) of said second planetary gear set (13) during operation of second forward speed; a third brake means (B3) for anchoring the ring gear (R3) of said third planetary gear set (14) and and the pinion carrier (16) of said second planetary gear set (13) during operation of reverse speed; and a one-way brake means (32) for preventing the ring gear (R3) of said third planetary gear set (14) and the pinion carrier (16) of said second planetary gear set (13) from rotating in a direction opposing to the rotation of said input shaft (10).
 2. A gear train as claimed in claim 1, further comprising: an engine output shaft (10b) driven by an engine; a torque converter (46) having a turbine (T) connected to said input shaft (10) and an impeller (P) connected to said engine output shaft (10b); a fourth planetary gear set (45a) having a ring gear (R4), and a planet pinion (P4) meshing with the ring gear thereof and rotatably journaled on the pinion carrier (17) of said third planetary gear set (14) and said output shaft (11), the planet pinion (P4) of said fourth planetary gear set (45a) being integral with the planet pinion (P3) of said third planetary gear set (14); and a third clutch means (C3) for engaging said engine output shaft (10B) with the ring Gear (R4) of said fourth planetary gear set (45a) during operation of fifth forward speed, with said first brake means (b1) being operated thereby to anchor the ring gear (R1) of said first planetary gear set (12). 